JPS6280338A - Back-up pressure controller for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the slip of a frictional element in engine brake application and prevent the fastening shock by controlling the back-up pressure according to the car speed on the selection from the automatic speed change range to the manual range. CONSTITUTION:A back-up pressure controller 200 is equipped with a throttle opening-degree detecting means 201, car-speed detecting means 202, range- position detecting means 203, coasting-state detecting means 204 and a gear position detecting means 205. Each detection signal of these detecting means 201-205 is input into a micro-computer 206. Therefore, the operation state in engine brake application is detected by the car-speed detecting means 202, and the back-up pressure corresponding to the operation state is supplied into an overrun clutch (frictional element) through the back-up pressure control means. Since an optimum back-up pressure is supplied into the frictional element, the shock on the fastening of the frictional element can be reduced to the min.

Description

[Detailed description of the invention]

Industrial Application Field The present invention relates to the control of an automatic transmission mounted on a vehicle, in which backup pressure is supplied to friction elements that are engaged during engine braking in order to prevent the friction elements from slipping. This invention relates to a backup pressure control device for an automatic transmission. Conventional Technology This type of backup pressure control device is described, for example, in the 1984 edition maintenance manual [Automatic Transaxle JRN4FO2A Model, RL] published by Nissan Motor Co., Ltd.
There is something like the one shown in the 4F'02A type (issued in February 1982). That is, the backup pressure control device used in this automatic transmission is equipped with a backup valve, and selects from 4th or 3rd speed in the automatic transmission range (D range) to the manual range (■ Lenz or I range) and shifts to 2nd speed. When the vehicle is downshifted, the backup valve is activated to supply the highest line pressure to the pressure modifier valve. Then, the signal pressure supplied from the pressure modifier valve to the pressure regulator valve is set high, and the line pressure regulated by the regulator valve is set even higher, and this high line pressure is used as a backup pressure to It is supplied to friction elements (clutches, band brakes, etc.) that are engaged in the manual range. That is, when shifting down from the D range high gear to the manual range, engine braking is applied, and during this engine braking, torque from the wheel direction acts on the friction element, but high engagement pressure (backup pressure) is applied to the friction element. By supplying this, the friction elements are prevented from slipping, thereby fully demonstrating the function of engine braking, and the friction elements are also prevented from being burnt out. Figure 9 shows the hydraulic pressure (
In the idling state when engine braking is applied, the backup pressure shown by the broken line is set to be significantly higher than the other line pressure characteristics shown by the solid line. Problems to be Solved by the Invention However, in such conventional backup pressure control devices, the backup pressure is always maintained at a constant level regardless of the vehicle speed when the engine brake is applied, that is, regardless of the magnitude of the torque input from the wheel side. It is now possible to Therefore, in order to prevent the friction elements from slipping, it is necessary to set the backup pressure at high vehicle speeds (D range'), 4th gear), and at lower vehicle speeds (D range, 3rd gear). When the engine brake is applied, if the backup pressure is set at high vehicle speeds, excessive engagement pressure will be applied, and when downshifting at low vehicle speeds, the engagement shock of the friction element will be significantly large, worsening ride comfort. There was a problem with it being put away. Therefore, the present invention is a backup pressure control device for an automatic transmission that prevents friction elements from slipping and also prevents engagement shock by controlling the backup pressure according to the operating state when engine braking is applied. The purpose is to provide Means for Solving the Problems In order to achieve the above object, the backup pressure control device for an automatic transmission of the present invention is designed to engage when the automatic transmission range is selected from the manual range, as shown in FIG. In an automatic transmission configured to supply backup pressure to a friction element (a) that is operated, a means (b) for detecting a vehicle speed when selecting a manual range, and a detection signal from the vehicle speed detecting means (b) are provided. It is constructed by providing means (C) for controlling the backup pressure. Operation With the above-described configuration, in the backup pressure control device for an automatic transmission of the present invention, the vehicle speed detecting means (b) detects the driving condition when the engine brake is applied, and the backup pressure corresponding to this driving condition is set as the backup pressure. Control means (
C) to the friction element (a). Therefore, the optimum backup pressure is supplied to the friction element (a), and even if the operating conditions during engine braking are different, the friction element (a) can be reliably fastened and the friction element (a) can be reliably engaged. ) The shock at the time of tightening can be minimized. EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings. That is, FIG. 2 shows an embodiment of a hydraulic pressure control device using the backup pressure control device of the present invention.
An example of a power transmission train for an automatic transmission is as shown in the schematic diagram of FIG. 3. That is, this power transmission train includes a torque converter 3 that transmits rotation from the engine output shaft 1 to the input shaft 2, a first planetary gear set 4, a second planetary gear set 5, and an output shaft 6.
, and various friction elements described below. The torque converter 3 is driven by the engine output shaft 1 and includes a pump impeller 3P that is also used to drive the oil pump O/P, and a turbine that is fluidly driven by the pump impeller via internal working fluid and transmits power to the human power shaft 2. It consists of a stator 3s placed on a fixed shaft via a launch 3T and a one-way clutch 7 to increase torque to the turbine launch 3T, and a lock-up clutch 3
This is a normal lock-up torque converter with L added. The torque converter 3 is supplied with working fluid from the release chamber 3R, and while the working fluid is removed from the apply chamber 3A, the lock-up clutch 3L is released and the engine power is transferred through the pump impeller 3P and the turbine launch 3T. (in the converter state) torque is transmitted to the input shaft 2 while increasing, and conversely, working fluid is supplied from the apply chamber 3A, and while the working fluid is removed from the release chamber 3R, the lock-up clutch 3L is engaged and the engine power is increased. is transmitted as is to the input shaft 2 via this lock-up clutch (in the lock-up state). In addition, in the latter lock-up state, the slip of the lock-up torque converter 3 (relative rotation of the pump impeller 3P and the turbine runner 3T) can be arbitrarily controlled (slip control) by reducing the working fluid displacement pressure from the release chamber 3R. can do. The first planetary gear set 4 is a normal simple planetary gear set consisting of a sun gear 4S, a ring gear 4R1, a pinion 4P that meshes with these gears, and a carrier 4C that rotatably supports the pinion 4P, and the second planetary gear set 5 is also a sun gear 5S. A simple planetary gear set consisting of a ring gear 5R, a pinion 5P, and a carrier 5C. Next, the various friction elements mentioned above will be explained. The carrier 4C can be appropriately connected to the input shaft 2 via a high clutch (L/C), and the sun gear 4S can be appropriately fixed to the input shaft 2 by a reverse clutch R/C. Can be combined. Further, the carrier 4C can be appropriately fixed by a multi-plate low reverse brake LR/B, and is prevented from being reversed (rotation in the opposite direction to the engine) via a row one-way clutch LO/C. The ring gear 4R is integrally connected to the carrier 5C and drivingly connected to the output shaft 6, and the sun gear 5S is connected to the human power shaft 2. The ring gear 5R can be appropriately connected to the carrier 4C via an overrun clutch OR/C, and is also correlated to the carrier 4C via a forward one-way clutch FO/C and a forward clutch F/C. Forward one-way clutch FO/C rotates ring gear 5R in the reverse direction (opposite direction to engine rotation) when forward clutch P/C is engaged.
It is assumed that the carrier 4C is coupled to the carrier 4C. High clutch I (/C, reverse clutch R/C, low reverse brake LR/B, overrun clutch O
The R/C and forward clutch F/C are each operated by the supply of hydraulic pressure to perform the above-mentioned appropriate coupling and fixing, but the band brake B/B is connected to the 2nd speed servo apply chamber 2S/A and the 3rd speed servo apply chamber 2S/A. When the release chamber 3S/R and the 4th speed servo apply chamber 4S/A are set and the 2nd speed selection pressure P is supplied to the 2nd speed servo apply chamber 2S/A, the band brake B/B is activated and this state When the 3rd speed selection pressure P3 is also supplied to the 3rd speed servo release chamber 3S/H, the band brake B/B becomes inactive, and then the 4th speed selection pressure P is also supplied to the 4th speed servo apply chamber 4S/A. Once supplied,
Band brake B/B is now activated. Such a power transmission train consists of friction elements B/B, I(/C, F
/C. By operating OR/C, LR/B, and R/C in the combinations shown in the table below, the friction elements FO/C, L
Together with the appropriate differential of the O/C, it is possible to change the rotational state of the elements constituting the planetary gear set 4.5, thereby changing the rotational speed of the output side 6 with respect to the rotational speed of the input shaft 2. 4 forward speeds and 1 reverse speed can be obtained as shown in the following table. Note that in the following table, the O mark indicates operation (hydraulic inflow), but the ::, ・marks indicate friction elements that should be activated when engine braking is required. And, like the Nini° mark (overrun clutch OR/
While C is operated, the forward one-way clutch FO/C disposed in parallel with it is inoperative, and while the low reverse brake LR/B is in operation, the row one-way clutch LO/C disposed in parallel with it is inoperative. Of course. Table 1 By the way, the hydraulic side control device shown in FIG. 2 includes a pressure regulator valve 20, a pressure modifier valve 22, a duty solenoid 24, a pilot valve 26
, torque converter regulator valve 28, lock-up control valve 30, shuttle valve 32, duty solenoid 34, manual valve 36, first shift valve 38, second shift valve 40, first shift solenoid 42, second shift solenoid 44, Forward clutch control valve 46. 3-2 timing valve 48. 4-2 relay valve 50.
4-2 Sequence valve 52, ■ Range pressure reducing valve 54, Shuttle valve 56, Overrun clutch control valve 58
, 3rd shift solenoid 6Q. Overrun clutch pressure reducing valve 63. 2nd speed servo apply pressure accumulator 64. 3rd speed servo release pressure accumulator 66, 4th speed servo apply pressure accumulator 68, which constitutes the main part of the shock reduction device of the present invention, and accumulator control valve 70 are the main components. These are the aforementioned torque converter 3, forward clutch F/C, high clutch H/C, and band brake B/B1.
Reverse clutch R/C Low reverse brake LR/
B, overrun clutch OR/C, and oil pump O/P are connected as shown in the figure. The pressure regulator valve 20 includes a spool 20b elastically supported in the left half position in the figure by a spring 20a, and a plug 20c abutting against the lower end surface of the spool in the figure. Basically, the oil pump O/P is connected to the circuit 71. The oil discharged to the line is regulated to a pressure determined by the spring force of the spring 20a, but when the upward force in the figure is applied to the spool 2Qb by the plug 20c, the above pressure is increased by that amount to reach the predetermined line pressure. It is something. For this purpose, the pressure regulator valve 2G is connected to the circuit 71 via the damping orifice 72.
Boats 20e to 20h are provided so that the pressure inside the spool 20b is received by a pressure receiving surface 20d of the spool 20b, thereby urging the spool 20b downward, and the boats 20e to 20h are opened and closed according to the stroke position of the spool 20b. The boat 2Qe is connected to the circuit 71 and is arranged so that as the spool 20b descends from the left half position in the figure, it communicates with the boats 20h and 2Of. As the spool 20b descends from the left half position in the figure, the communication between the boat 20f and the boat 20g, which is used as a drain port, decreases, and at the point when communication with this is cut off, the boat 20
Place it so that it begins to communicate with e. and boat 20f
is connected to the capacity control actuator 75 of the oil pump O/P via a circuit 74 with a bleed 73 in the middle. The oil pump O/P is a variable capacity vane pump driven by the engine as described above, and the eccentricity is controlled by the actuator 7.
It is assumed that when the pressure toward 5 exceeds a value, the capacity is reduced. The plug 20c of the pressure regulator valve 20 receives modifier pressure from the circuit 76 on its lower end face in the figure, and receives backward selection pressure from the circuit 77 on its pressure receiving surface 20i, and generates an upward force in the figure corresponding to these pressures. . It shall be added to the spool 20b. The pressure regulator valve 20 is normally in the left half state in the figure, and when oil is discharged from the oil pump O/P, this oil flows into the circuit 71. Spool 2
At the left half position of Qb, the oil in the circuit 71 is not drained and the pressure increases. This pressure acts on the pressure receiving surface 20d through the orifice 72, pushes down the spool 20b against the spring 20a, and connects the boat 20e to the boat 20h. As a result, the above pressure is partially drained from the boat 20h and lowered, and the spool 20b is pushed back by the spring 20a. By repeating this action, the pressure regulator valve 20 basically sets the pressure within the circuit 71 (hereinafter referred to as line pressure) to a value corresponding to the spring force of the spring 20a. Incidentally, an upward force is applied to the plug 20c due to the modifier pressure from the circuit 76, so that the plug 20c is in the right half state in the figure (abutting against the spool 20b, and this upward force assists the spring 20a). The above line pressure is applied to the spool 20b, and the modifier pressure is generated when the reverse is not selected as described later, and increases in proportion to the engine load (engine output torque). When the reverse selection pressure is selected, an upward force is applied to the plug 20c by the reverse selection pressure (same value as the line pressure) from the circuit 77 instead of the modifier pressure, and this is applied to the spool 20b, so that the line pressure increases. becomes a desired constant value when the reverse is selected.When the rotation speed exceeds the oil pump O/P (or higher than the engine rotation speed), the oil discharge amount that increases accordingly becomes excessive, and the pressure in the circuit 71 increases. This pressure lowers the spool 20b further from the pressure adjustment position in the right half of the figure, and connects the point 2Of to the boat 20e.
Drainpo) Cut off from 20g. As a result, some of the oil in the boat 20e is removed from the port 2Of and the bleed 73, but feedback pressure is generated within the circuit 74. This feedback pressure increases as the rotational speed of the oil pump O/P increases, and reduces the eccentricity (capacity) of the oil pump O/P via the actuator 75. In this way, the capacity of the oil pump O/P is controlled so that the discharge amount remains constant while the rotational speed exceeds a certain value, thereby preventing an increase in power loss of the engine due to discharge of more than necessary oil. The line pressure generated in the circuit 71 as described above is supplied to the pilot valve 26, the manual valve 36, the accumulator control valve 70, and the 3-speed servo release pressure accumulator 66 through the line pressure circuit 78. The pilot valve 26 includes a spool 26b elastically supported in the upper half position in the figure by a spring 26a, the end face of the spool 26b far from the spring 26a faces the chamber 26c, and the pilot valve 26 is further provided with a drain port 26d. , a pilot pressure circuit 79 with strainer S/T is maintained. A communication hole 26e is provided in the spool 26b to guide the pressure of the pilot pressure circuit 79 to the chamber 26c.
It shall be switched and connected to d. The pilot valve 26 is normally in the upper half state in the figure, and when it is supplied with line pressure from the circuit 78, it increases the pressure in the circuit 79. The pressure in the circuit 79 reaches the chamber 26c through the communication hole 26e, causing the spool 26b to move to the right in the figure, and when the spool 26b exceeds the pressure regulating position shown in the lower half of the figure,
The circuit 79 is disconnected from the circuit 78 and at the same time is connected to the drain boat 2.6d. At this time, the pressure in circuit 79 is reduced,
When the spool 26b is pushed back by the spring 26a due to this pressure drop, the pressure in the circuit 79 increases again. Pilot valve 26 thus directs line pressure from circuit 78 to spring 26a.
The pressure can be reduced to a constant value determined by the spring force and output to the circuit 79 as pilot pressure. This pilot pressure is transmitted through a circuit 79 to the pressure modifier valve 22, the duty node 24, 34, the lockup control valve 30, the forward clutch control valve 46, the shuttle valve 32, the first . ° Supplies the second and third shift solenoids 42, 44, 60 and shuttle valve 56. The duty solenoid 24 includes a coil 24a, a spring 24d, and a plunger 24b, and has an orifice 80.
The circuit 81 connected to the pilot pressure circuit 79 via
When the coil 24a is turned on (energized), it communicates with the drain port 24c. The duty node 24 is controlled by a computer (not shown) to turn on and off the coil 24a at a constant cycle, and to control the ratio of the ON time to the constant cycle (duty ratio).
1 to generate a control pressure according to the duty ratio. The duty ratio is made smaller as the engine load (for example, engine throttle opening) increases except when the reverse is selected, and thereby the above-mentioned control pressure is made higher as the engine load increases. Further, the duty ratio at the time of reverse selection is set to 100%, and the above-mentioned control pressure is set to 0. The pressure modifier valve 22 includes a spool 22b that is biased downward in the figure by a spring 22a and control pressure from the circuit 81, and the pressure modifier valve 22 further has an output capo 22c connected to the circuit 76. An input port 22d to which the pilot pressure circuit 79 is connected and a drain boat 22e are provided, and a spring 22a is connected thereto. Then, the boat 22 is located at the left half position of the spool 22b in the figure.
These ports are arranged so that C is isolated from ports 22d and 22e. The pressure modifier valve 22 receives the spring force of the spring 22a and the force of the control pressure from the circuit 81 downward in the figure on the spool 22b, and transmits the force due to the output pressure from the port 22c reaching the chamber 22f to the spool 22b. Spool 2 is placed in a position where these forces are balanced.
2b is stroked. If the output pressure from the port 22c is insufficient to match the downward force, the spool 22b descends beyond the pressure regulating position shown in the left half. At this time, the boat 22c communicates with the port 22d and receives pilot pressure from the circuit 79 to increase its output pressure. Conversely, if this output pressure is too high to match the downward force, the spool 22b will rise toward the right half position in the figure. At this time, the port 22c communicates with the drain boat 22e, and the output pressure is reduced. By repeating this action, the pressure modifier valve 22 is
hr11″ tree (f f3992) if wa cal rg r
2i11a Adjust the pressure to a value corresponding to the phase of the force by the control pressure of R+61^, and use this as a modifier pressure from the circuit 76 to the plug 20c of the pressure regulator valve 20.
supply to. By the way, as mentioned above, the control pressure increases as the engine load increases except when the reverse is selected, and since it is O when the reverse is selected, the modifier is set to a value obtained by amplifying this control pressure by the spring force of the spring 22a. The pressure also increases as the engine load increases except when the reverse is selected, and becomes 0 when the reverse is selected, enabling the above-mentioned line pressure control by the pressure regulator valve 20.The torque converter regulator valve 28 is connected to the right half of the figure by a spring 28a. A spool 28b is elastically supported in a position,
While the spool strokes between the right half position in the figure and the left half position in the figure, the boat 28c is passed through the boat 28d, and as the spool 28b rises from the left half position in the figure, the boat 28c is moved relative to the boat 28d. The degree of communication shall be decreased with respect to the boat 28e, and the degree of communication shall be increased with respect to the boat 28e. Spring 28 is used to control the stroke of spool 28b.
The chamber 28f facing the spool end face far from a is the spool 28
It communicates with the boat 28c through the communication hole 28g provided in b. The boat 28c is connected to a predetermined lubricating part via a relief valve 82 and connected to the lock-up control valve 30 via a circuit 83, and the boat 28d is connected to the boat 2 of the pressure regulator valve 20 via a circuit 84.
0h, and boat 28e is connected to lockup control valve 30 by circuit 85. The circuit 85 has an orifice 86 in the middle, and the orifice and the port 211
1c is connected to a circuit 83 via an orifice 87 and communicated with an oil cooler 89 and a predetermined lubricating section 90 via a circuit 88. The torque converter regulator valve 28 is normally in the right half state in the figure, and when oil is supplied from the boat 20h of the pressure regulator valve 20 via the circuit 84, this oil is transferred from the circuit 83 to the "torque converter" as described later. Head to 3. When supply pressure to the torque converter is generated, this torque converter supply pressure reaches the chamber 28f through the communication hole 28g, causing the spool 28b to rise in the figure against the spring 28a. When the spool 28b rises from the left half position in the figure due to an increase in the torque converter supply pressure, the boat 28e opens and a portion of the torque converter supply pressure is removed through the boat 28e and the circuit 88, thereby increasing the torque converter supply pressure. The pressure is adjusted to a value determined by the spring force of the spring 28a. The oil removed from the circuit 88 is cooled by an oil cooler 89 and then directed to the lubricating section 9o. Note that if the torque converter supply pressure exceeds the above value due to the pressure regulating action of the torque converter regulator valve 28, the relief valve 82 opens and releases the excess pressure to the corresponding lubricating part to prevent deformation of the torque converter 3. do. The lock-up control valve 3o is constructed by coaxially abutting a spool 30a and a plug 30b, and the spool 30a
When the spool 30a is at the limit position shown in the right half of the figure, the circuit 83 is connected to the circuit 91 from the torque converter release chamber 3R, and when the spool 30a is lowered to the left half position in the figure, the circuit 83 is connected to the circuit 85. When the spool 30a further descends, the circuit 9I is connected to the drain port 30c. Stroke rotation & I-J-puff of such spool 30a is 1-1+-shi08 1) Whisper・-J・30a
The end face of the plug 30b faces the chamber 30d, and the pressure of the circuit 91 is led through the orifice 92 to the chamber 30e, which faces the end face of the plug 30b far from the spool 30a. Note that the circuit 93 from the torque converter apply chamber 3A is connected to the orifice 8.
6 is connected to the circuit 85 at a location closer to the lockup control valve 30. In addition, the pilot pressure from the circuit 79 is applied to the plug 30b through the orifice 94 to continue applying a downward force in the figure, thereby preventing pulsation of the spool 30a. The lock-up control valve 3o controls the stroke of the spool 30a by the pressure supplied to the chamber 30d, and as long as this pressure is sufficiently high, the spool 30a maintains the right half position in the figure. At this time, oil from circuit 83 flows through circuit 91, release chamber 3R, apply chamber 3, circuit 93, and circuit 85 under pressure regulation by torque converter regulator valve 28, and is removed from circuit 88. Thus torque converter 3
transmits power in the converter state. As the pressure inside the chamber 30d decreases, the sprue IL Rn A I+-+
II M/j Q Q OJ As-1In d + l-t, h When it is lowered in the figure through the plug 30b and further lowered from the left half position in the figure, the pressure regulating oil from circuit 83 is transferred to circuit 85.93. , the apply chamber 3A, the release chamber 3R, the circuit 91, and the drain boat 30c, and the torque converter 3 transmits power under a slip control state in which the slip decreases as the pressure in the chamber 30d decreases. When the pressure in the chamber 30d is further reduced from this state, the circuit 91 is completely communicated with the drain boat 30c due to the further lowering of the spool 30a, and the pressure in the release chamber 3R is reduced to 0, and the torque converter 3 is in a locked-up state and the power is communicate. The shuttle valve 32 controls the stroke of the lock-up control valve 30 together with a forward clutch control valve 46 (to be described later), and includes a spool 32b elastically supported in the lower half position in the figure by a spring 32a. Switch to the upper half position in the figure as appropriate depending on the pressure. When the spool 32b is in the lower half position in the figure, the shuttle valve 32 connects the circuit 95 of the wheel 30d to the pilot circuit 7.
9, and a circuit 96 extending from the chamber 46a of the forward clutch control valve 46 is connected to a circuit 97 from the duty solenoid 34.
When 2b is in the upper half position in the figure, the circuit 95 is connected to the circuit 97, and the circuit 96 is connected to the circuit 79. The duty solenoid 34 includes a coil 34a and a spring 34.
A circuit 97 consisting of a plunger 34b elastically supported in the closed position at d and connected to a bi-lot pressure circuit 79 through an orifice 98 is connected to the drain boat 34c when the coil 34a is turned on (energized). The duty solenoid 34 is connected to the coil 3 by a computer (not shown).
4a is controlled to turn on and off at a constant cycle, and the ratio of the ON time to the constant cycle (duty ratio) is controlled to generate a control pressure in the circuit 97 according to the duty ratio. When the shuttle valve 32 is in the upper half position in the figure, the circuit 97
When the control pressure is used to control the stroke of the lock-up control valve 30, the duty ratio of the solenoid 34 is determined as follows. Under high load and low rotation speeds of the engine where the torque increasing function and torque fluctuation absorbing function of the instant torque converter 3 are absolutely necessary, the duty ratio is set to 0%, thereby controlling the control pressure of the circuit 97 to the original pressure. Make it the same as the pilot pressure of a certain circuit 79. At this time, the control pressure maintains the spool 30a in the right half position in the figure in the chamber 30d, and maintains the torque converter 3 in the converter state to meet the above requirements. As the requirements for both of the above functions of the torque converter 3 become lower, the duty ratio is increased and the control pressure is lowered.
0, the torque converter 3 is operated in a slip control state that matches the demand, and the duty ratio is set to 100% under low engine load and high engine speed where the above-mentioned functions of the torque converter 3 are not required. The control pressure is set to 0 and the torque converter 3 is maintained in the lock-up state as required via the lock-up control valve 30. Note that when the shuttle valve 32 is in the lower half state in the figure and the control pressure of the circuit 97 is used to control the stroke of the forward clutch control valve 46, the dew valve of the solenoid 34,
/l + ke 2 discussion between candy → D select S It is determined to reduce the stress and prevent creep. The manual valve 36 can be set in the parking (P) range, reverse (R) range, neutral (N) range, or
Forward automatic transmission (D) range, forward 2nd speed engine brake (II) range, forward 1st speed engine brake (I)
A spool 36a that is stroked in a range is provided, and a line circuit 78 is connected to ports 36D, 36■, 36I, and 36R according to the selected range of the spool as shown in the following table. Note that in this table, O marks indicate ports that communicate with the line pressure circuit 78, and no marks indicate ports that are drained. The first shift valve 38 includes a spool 38b elastically supported in the left half position in the figure by a spring 38a.
It is assumed that when pressure is supplied to 8c, it is switched to the right half position in the figure. The first shift valve 38 changes the boat 38d to the drain boat 38e when the spool 38b is in the left half position.
The boat 31H is connected to the boat 38g, the boat 38h is connected to the boat 38i, and when the spool 38b is in the right half position in the figure, the boat 38d is connected to the boat 38j, the boat 38f is connected to the boat 38k, and the boat 38h is connected to the boat 3812. shall be allowed to do so. The second shift valve 40 includes a spool 40b elastically supported in the left half position in the figure by a spring 40a.
When pressure is supplied to 0c, it is assumed to be in the right half position in the figure. When the spool 40b is in the left half position in the figure, the second shift valve 40 allows the boat 40d to communicate with the drain boat 40e, the boat 40f with the boat 40g, and the boat 40h with the orifice-equipped drain boat 40i.
When is in the right half position in the figure, change boat 40d to boat 40j,
It is assumed that the boat 40f is connected to the drain boat 40e, and the boat 40h is connected to the boat 40k. The spool positions of the first and second shift valves 38,40 are the first shift solenoid 42 and the second shift solenoid 4, respectively.
These shift solenoids are controlled by coils 42a, 44a and plungers 42b, respectively.
44b, and springs 42d and 44d. 1st
Shift solenoid 42 is connected to pilot pressure circuit 79 via orifice 99, and circuit 10 leading to chamber 38c.
0, when the coil 42a is ON (energized), the drain boat 42
c, and the control pressure in the circuit 100 is set to the same value as the pilot pressure, which is the source pressure, thereby switching the first shift valve 38 to the right half state in the figure. Further, the second shift solenoid 44 is connected to the pilot pressure circuit 79 via the orifice 101, and connects the circuit 102 to the chamber 40c.
When the coil 44a is turned on (energized), it is cut off from the drain boat 44c to make the control pressure in the circuit 102 the same value as the pilot pressure of the source pressure, thereby switching the second shift valve 40 to the right half state in the figure. do. The 1st to 4th forward speeds can be obtained by the combination of ON and OFF of these shift solenoids 42 and 44, and therefore the states of the shift valves 38 and 40, which are summarized in the table below. . In Table 3, the O mark in this table indicates the right half of the shift valve in the figure (ascending), the X mark indicates the left half of the shift valve in the figure (descending), and the shift solenoid 42 and 44. ON. OFF is determined by a computer (not shown) that determines a suitable gear position based on the vehicle speed and engine load based on a predetermined gear change pattern, and determines the appropriate gear position. Forward clutch computer valve 46 is connected to spool 46
b, and the pilot pressure from the circuit 79 guided through the orifice 103 is applied downward in the figure to prevent pulsation of the spool, and the spool is further provided with a pilot pressure in the circuit 105 through the orifice 104. The operating pressure of the forward clutch F/C is fed back and applied downward in the figure. The spool 46b is stroked to a position where the downward force in the figure due to these pressures and the force due to the pressure inside the chamber 46a are balanced. Spool 46
b is the right-hand position in the figure when the circuit 105 is connected to the drain port 46.
C, and the circuit 105 is connected to the circuit 106 at the left half position in the figure.
The circuit 105 is provided with a one-way orifice 107 that exerts a throttling effect only on the hydraulic pressure toward the forward clutch F/C, and the circuit 106 is connected to the boat 36D of the manual valve 36. 3-2 Timing valve 48 includes a spool 48b elastically supported at the left half position in the figure by a spring 48a, and at this spool position the boat 48c and the boat 4 with the orifice 48f
8a, the pressure inside the chamber 48e is high, and the spool 4
When 8b is in the right half position in the figure, boats 48c and 48a
The gap shall be cut off. 4-2 The relay valve 50 includes a spool 50b elastically supported at the left half position in the figure by a spring 50a, and at this spool position, the boat 50c is connected to the drain boat 50d with an orifice, and pressure is supplied into the chamber 50e. When the spool 50b is at the right half position in the figure, the boat 50c is connected to the boat 50f. 4-2 The sequence valve 52 includes a spool 52b that is elastically supported at the right half position in the figure by a spring 52a, and at this spool position, the boat 52c is connected to the drain boat 52 with an orifice.
d, and when the pressure in the chamber 52e is high and the spool 52b is at the left half position in the figure, the boat 52c is connected to the boat 52f. The I range pressure reducing valve 54 includes a spool 54b biased toward the right half position in the figure by a spring 54a, and has bows 54c and 54d that communicate with each other at this spool position, and the spool 54b is biased toward the left half position in the figure. A drain boat 54e is provided which begins to communicate with the boat 54c when the boat 54d is closed. A chamber 54f facing the end face of the spool 54b far from the spring 54a is connected to the boat 54c via an orifice 108. Thus, I range pressure reducing valve 54
is normally in the right half state in the figure, and when pressure is supplied to the boat 54d, pressure is output from the boat 54c. This output pressure is passed through the orifice 108 to the spool 54b.
It acts on the lower end surface in the figure, and as the output pressure increases, the spool 54b is raised in the figure. When the spool 54b rises above the left half position in the figure, the bow 54c is connected to the drain port 54.
e, the output pressure from boat 54c is reduced. When the spool 54b descends beyond the left half position in the figure due to this output pressure drop, the boat 54c communicates with the boat 54d.
The output pressure from boat 54c is increased. By repeating this action, the output pressure from the boat 54c is reduced to a constant value determined by the spring force of the spring 54a. The shuttle valve 56 includes a spool 56b elastically supported in the left half position in the figure by a spring 56a, and this spool is connected to the chamber 56.
It is held in this position when there is a pressure supply to g, but chamber 5
While no pressure is supplied to the boat 56c, when the upward force in the figure due to the pressure from the boat 56c exceeds the value, it is stroked to the right half position in the figure. At the left half position in the figure, the boat 56d is connected to the circuit 109 from the third shift solenoid 60, and the boat 56e is connected to the drain port 56f.
The boat 56d is connected to the pilot pressure circuit 79 at the right half position in the figure.
Assume that the boat 56e is connected to the circuit 109. The third shift solenoid 60 includes a coil 60a, a plunger 60b, and a spring 60d.
circuit 109 connected to pilot pressure circuit 79 via 0
When the coil 60a is ON (energized), the drain boat 60c
The control pressure in the circuit 109 is set to the same value as the pilot pressure, which is the source pressure. Note that whether the third lift solenoid 60 is turned on or off is determined by a computer (not shown). Overrun clutch computer valve 58 is spring 58a
It is assumed that a spool 58b is elastically supported in the left half position in the figure, and this spool is switched to the right half position in the figure when pressure is supplied to the chamber 58'c. Also, the spool 58b connects the boat 58d to the drain port 58e and the boat 58f to the boat 58g at the left half position in the figure, and connects the boat 58d to the boat 58h and the boat 58f to the drain port 58e at the right half position in the figure. It is assumed that the The overrun clutch pressure reducing valve 62 includes a spool 62b elastically supported in the left half position in the figure by a spring 62a, and when there is pressure from a boat 62c on this spool, this applies a downward force in the figure. Hold the spool 62b in this position. When pressure is supplied to boat 62d while there is no pressure inflow from boat 62c, this pressure increases the output pressure from boat 62e. This output pressure is in the chamber 62f
When it reaches a value corresponding to the spring force of the spring 62a, the spool 62b is moved to the right half position in the figure to cut off the connection between the boats 62d and 62a, and the overrun clutch pressure reducing valve 62 transfers the output pressure from the boat 62e to the spring force. 62a
Assume that the pressure is reduced to a constant value determined by the spring force. The 2-speed servo apply pressure accumulator 64 includes a service piston 64a elastically supported in the left half position in the figure by a spring 64b, and a chamber 6 defined between both ends of the service piston 64a.
4c is opened to the atmosphere, and the small diameter end face and large diameter end face of the service piston are made to face the closed chambers 64d and 64e, respectively. - The 3-speed servo release pressure accumulator 66 is constructed by elastically supporting a service piston 66a at the left half position in the figure by a spring 66b, and connects a chamber 66c defined between both ends of the service piston to the line pressure circuit 78. The small diameter end face and the large diameter end face of the service piston are connected to each other in a sealed chamber 66d. 66e. The 4th speed servo apply pressure apply pressure 68 is constituted by a stepped piston 68a elastically supported at the left half position in the figure by a spring 68b, and a sealed chamber 68c is defined between both ends of the stepped piston. The small-diameter end face and large-diameter end face of the piston face the closed chambers 68d and 68e, respectively. The accumulator control valve 70 includes a spool 70b elastically supported in the left half position in the figure by a spring 70a, and a chamber 70c facing the end face of the spool 70b far from the spring 70a.
The control pressure of the circuit 81 is guided to. The spool 70b connects the output port door 0d to the drain port 70e at the left half position in the figure, and when the control pressure to the chamber 70c becomes high and the spool 7Qb rises above the right half position in the figure, the boat 70d is connected to the line pressure circuit. 78 shall be switched and connected. Then, the output port door 0d is connected to the accumulator chamber 64d by the circuit 111.
, a chamber 7 connected to 68c and housing a spring 70a.
Also connect to 0f. Thus, the accumulator control valve 70 raises the spool 70b above the right half position in the figure by the control pressure applied to the chamber 70c except when the reverse movement is selected. As a result, the line pressure from the circuit 78 is output to the circuit 111, and when the pressure in the circuit 111 reaches a value corresponding to the control pressure, the spool 70b is elastically supported at the right half position in the figure. Therefore, the pressure in the circuit 111 is regulated to a value corresponding to the control pressure, but
Since the control pressure increases as the engine load (engine output torque) increases except when reverse is selected as described above, circuit 1
11 to chambers 64d, 68 of accumulators 64.68
The pressure supplied to c as accumulator back pressure also increases as the engine output torque increases. In addition, since the control pressure is 0 when the reverse movement is selected, no pressure is output to the circuit 111. Next, to provide a supplementary explanation of the hydraulic circuit network, the circuit 106 extending from the port 36D of the manual valve 36 is connected to the port 38g of the first shift valve 38 and the port 40g of the second shift valve 40, and the circuit 106 extends from the port 36D of the manual valve 36. It is also connected to port 56c of shuttle valve 56 and port 58g of overrun clutch control valve 58 via a more branched circuit 112. The port 38f of the first shift valve 38 is connected to the circuit 11
3 to the port 50f of the 4-2 relay valve 50, and is also connected to the accumulator chamber 64e and the 2-speed servo apply chamber 2S/A via the one-way orifice 114, and the port 50f is connected to the shuttle valve 32 by the circuit 115.
It is also connected to the chamber 32c. Furthermore, the port 38h of the first shift valve 38 is connected to the chamber 5 of the 4-2 relay valve 50 by the circuit 116.
0e and port 58h of overrun clutch control valve 58 1. : connected, and the 4-2 relay valve 5o node 50c is connected to the port 40k of the second shift valve 4o by a circuit 117. 38Q is connected to the port 38 of the first shift valve 38 and the port 40f of the second shift valve 40 to the high clutch H/C by a circuit 118, and a pair of one-way orifices 119.120 are arranged in opposite directions in the middle. Insert. A circuit 121 branched from the circuit 118 between these orifices and the high clutch H/C is connected to the 3-speed servo release chamber 3S/R and the accumulator chamber 66e via the one-way orifice 122, and a circuit 123 that bypasses the one-way orifice 122 Connect ports 48c and 48d inside 3-2
A timing valve 48 is inserted into this circuit 123. One-way orifice 122 and 3-speed servo release chamber 3S
The circuit 124 branching from the circuit 121 between /R is 4
- Connect to the chamber 52e of the 2-2 sequence valve 52, and connect the ports 52c and 52f of the 4-2 sequence valve 52 to the first
It is connected to the port 38i of the shift valve 38 and the port 40h of the second shift valve 40. The port 38j of the first shift valve 38 is connected to the port 40d of the second shift valve 40 by the circuit 125, and the port 38j is connected to the port 40d of the second shift valve 40.
is connected by circuit 126 to one inlet port of shuttle ball 127. The other inlet boat of the shuttle ball 127 is connected by a circuit 128 on the one hand to the port 36R of the manual valve 36 together with said circuit 77 and on the other hand to the reverse clutch R/
C and the accumulator chamber 68d, and the exit boat of the shuttle ball 127 goes up to the circuit 130 and is connected to the low reverse brake LR/B. The boat 40j of the second shift valve 40 is connected to the port 54c and chamber 54f of the I-range pressure reducing valve 54 through a circuit 131, and the I-range pressure reducing valve 54
The port 54d of the manual valve 36 is connected by the circuit 132 to the port 36I of the manual valve 36. The port 56e of the shuttle valve 56 is connected to the 3-
2 connected to the chamber 48e of the timing valve 48, and the boat 56d
is connected to chamber 58c of overrun clutch control valve 58 by circuit 134. The boat 58d of the overrun clutch control valve 58 is connected to the accumulator chamber 66d by a circuit 135, and is connected to the accumulator chambers 68e and 4 through a one-way orifice 136.
Connect to speed servo apply chamber 4S/A. The boat 58f of the overrun clutch control valve 58 is connected to the boat 62d of the overrun clutch pressure reducing valve 62 by a circuit 137, and the boat 62e of the pressure reducing valve 62 is connected to the overrun clutch OR/C by a circuit 138.
A check valve 139 is provided between circuits 137 and 138. The boat 62c of the overrun clutch pressure reducing valve 62 is connected to the boat 36n of the manual valve 36 and the chamber 56g of the shuttle valve 56 by a circuit 140. The operation of the hydraulic circuit in the forward travel range will now be described. Pressure regulator valve 20. The pressure modifier valve 22 and the duty solenoid 24 have the above-mentioned functions to regulate the oil from the oil pump 0/P to a line pressure that increases in proportion to the engine output torque, except when the reverse is selected, and when the reverse is selected, the oil from the oil pump 0/P is increased. The oil from P is kept at a constant value and is output to the circuit 78. This line pressure is controlled by the pilot valve 26° and the manual valve 36. The accumulator control valve 70 and the accumulator 66 are reached, and the accumulator 66 is placed in the right half state in the figure. The accumulator control valve 70 applies the accumulator back pressure proportional to the engine output torque to the accumulator 64.6 through the circuit 111 by the above operation except when the reverse is selected.
8 chambers 64d and 68c, and these accumulators are in the right half state in the figure. Incidentally, when the backward movement is selected, the accumulator control valve 70 sets the accumulator back pressure to 0 as described above, and the accumulators 64 and 68 are placed in the left half state in the figure. Further, the pilot valve 26 always outputs a constant pilot pressure to the circuit 79 due to the front activation effect. If the P or N range driver does not wish to drive and sets the manual valve 36 to the P or N range, the manual valve boat 36D, 3
6II, 361, and 36R are all drain boats as shown in Table 2 above, and line pressure is not output from these boats, so the forward clutch F/C is operated using the line pressure from these boats as source pressure. , high clutch H/C, band brake B/B, reverse clutch R/, C, low reverse brake LR/B, and overrun clutch ORP are all kept inoperative, and the second
The power transmission train shown in the figure can be kept in a neutral state in which power cannot be transmitted. In a state where the manual valve 36 is set to the D range with the desire for forward travel in the D range, automatic gear shifting is performed as follows. (First speed) That is, in the D range, the manual valve 36 outputs the line pressure from the circuit 78 to the boat 36D as shown in Table 2 above. The line pressure from Bonito 36D is set as D range pressure by circuit 106.

[Shift valve 38 boat 38g, 2nd
It is supplied to the boat 40g of the shift valve 40 and the forward clutch control valve 46, and is also supplied by the circuit 112 to the boat 56c of the shuttle valve 56 and the boat 58g of the overrun clutch control valve 58. On the other hand, when the vehicle is stopped in the D range, the computer automatically switches between the first shift solenoid 42 and the second shift solenoid 44.
Both ONL, the first shift valve 38 and the second shift valve 40
Both are in the right half state in the figure. For this reason, high clutch H
/C is connected from the circuit 118 to the drain boat 40e via the boat 40f and becomes inactive. In addition, the 2nd speed servo apply chamber 2S/A connects from the circuit 113 to the boats 38f, 38, (ittg, baud) 40f to the Tetren boat 40e, and the 3rd speed servo release chamber 3S/R connects to the circuits 121, 1.
18. Connects to drain boat 40e via boat 4Gf,
Since the 4-speed servo apply chamber 4S C communicates with the same drain boat 40e as described below, the band brake B/B is also inoperative. In other words, while the engine output torque is above a certain level,
The D range pressure (line pressure) from the boat 56c, which is proportionally higher, puts the shuttle valve 56 in the right half state in the figure and supplies the pilot pressure of the circuit 79 from the circuit 134 to the overrun clutch control valve 58. Place the valve in the right half position in the figure. Further, even when the engine output torque is below a certain level and the shuttle valve 56 is in the left half state in the figure, if there is no engine brake request operation, which will be described later, at this time, the circuit 109 to circuit 1
34 to the overrun clutch control valve 58, the computer transfers the control pressure to the third shift solenoid 6.
By turning on 0, the value is set to the same value as the pilot pressure, and the overrun clutch control valve 58 is placed in the right half state in the figure. Therefore, at this time, the 4th speed servo apply pressure 4S/A is applied to the circuit 135. 58d, 58h, circuit 116° boat 38h, 38Q, circuit 118. As described above, it leads to the drain boat 40e via the boat 40f. Further, the reverse clutch R/C is drained from the boat 36R via the circuit 128 and is in an inoperative state, and the low reverse brake LR/B is also drained as described below and is in an inactive state. That is, one inlet circuit 128 leading to the shuttle ball 127 associated with the circuit 130 to the low reverse brake LR/B is drained as described above, and the other circuit 126 is also drained (38d, 38j). Circuit 125. ■The range pressure reducing valve 54 connected to the boats 40d and 40f via the circuit 131 is connected to the manual valve boat 36.
Since it is not receiving pressure supply from I, it is in the right half state in the figure and is drained from the boat 361, so the low reverse brake LR/B is in an inoperative state as described above. Next, the overrun clutch OR/C is operated by the check valve 139 from the circuit 138 because the overrun clutch control valve 58 is in the right half state in the figure as described above.
It communicates with the drain boat 58e via the boat 58f, and is in an inactive state. As mentioned above, since there is no pressure in the circuit 113 heading towards the 2nd speed servo apply chamber 2S/A, the circuit 1
The shuttle valve 32 connected to the chamber 32c through the valve 15 is shown in the lower half of the figure. Therefore, this shuttle valve 32 is connected to the circuit 9
The pilot pressure from the circuit 79 is supplied to the chamber 30d from 5, and the lock-up control valve 30 is kept in the right half state in the figure, thereby setting the torque converter 3 in the converter state. Shuttle valve 32 further connects circuit 97 to chamber 46a from circuit 96.
The forward clutch control valve 46 is controlled as follows by supplying control pressure from
I can do it. That is, when the D range and the aperture are not performing a starting operation (releasing the brake and depressing the accelerator pedal when the vehicle speed is 0), the duty ratio of the solenoid 34 is set to 100% and the control pressure to the chamber 46a is applied. Set to 0. As a result, the forward clutch control valve 46 is in the right half state in the figure, and even though the D range pressure is output to the circuit 106 as described above, this is the forward clutch F/
C is not reached and it is kept inactive. And high clutch H/C, band brake B/B
. Reverse clutch R/C, low reverse brake LR/
B. Since the overrun clutch OR/C is also inactive as mentioned above, the automatic transmission will remain in a neutral state in which power cannot be transmitted unless a starting operation is performed even in the D range, resulting in a creep phenomenon or a shift from the N range to the D range. It is possible to prevent a select shock (N→D select shock) at the time of switching. When the driver performs a start operation, the computer gradually decreases the duty ratio of the solenoid 34 until it finally reaches 0%. As a result, the control pressure to the chamber 46a gradually increases, and finally reaches the same value as the pilot pressure of the circuit 79, which is the source pressure. During this time, the forward clutch control valve 46 is gradually switched from the right half state in the figure to the left half state in the figure, and the circuit 105
Gradually increase the pressure towards the forward clutch F/C from
Finally, it becomes the same value as the D range pressure (line pressure) from the circuit 106. Therefore, the forward clutch F/C is gradually operated,
As shown in Table 1 above, forward one-way clutch FO/
In conjunction with the operation of C and row one-way clutch LO/C, the automatic transmission becomes the first speed selection state, and the vehicle can be started. Furthermore, at this time of starting, in order to gradually increase the working oil pressure of the forward clutch F/C as described above,
In addition, in conjunction with the throttling effect of the one-way orifice 107, the forward clutch F/C operates at a predetermined speed, making it possible to prevent start shock. (Second speed) After that, when the vehicle speed increases and the driving state becomes such that the second speed should be selected, the computer switches the first shift solenoid 42 to OFF as shown in Table 3 above, and the first shift valve 3
8 to the left half state in the figure. - This causes the first lift valve 38 to drain the circuit 126 through the drain port 38e, and connect the circuit 11G to the boats 38h, 38i and 4-2 sequence valve 52.
(This valve is currently in the right half state in the figure because no pressure is supplied to the 3rd speed servo release chamber 3S/H).The valve continues to drain by communicating with the drain boat 52d via the boat 52c. However, the first shift valve 38 connects the circuit 113 to the circuit 106, and also supplies the D range pressure to the second speed servo apply chamber 2S/A through the circuit 113, and operates the band brake B/B. Forward clutch F/
C operation maintenance and forward one-way clutch FO/
Coupled with the operation of C, the automatic transmission enters the second speed selection state, as is clear from Table 1 above. During this upshift from 1st speed to 2nd speed, the hydraulic pressure to the 2nd speed servo apply chamber 2S/A is throttled by the one-way orifice 114, pushing the accumulator piston 64a located at the right half position in the figure as described above. Since the band brake B/B gradually rises while moving, the operation of the band brake B/B proceeds gradually, and the shock at the time of the gear change can be alleviated. Then, the chamber 6 surrounding the accumulator piston 64a
Since the back pressure within 4d is proportional to the engine output torque as described above, the shift shock reducing effect described above can be reliably achieved. Note that, as is clear from Table 1 above, not only the second speed but also the third and fourth speeds are selected, the second speed servo apply chamber 2S
Since the D range pressure is supplied to /^, the shuttle valve 32, which is supplied with this pressure to the chamber 32c by the circuit 115, maintains the upper half state in the figure during selection of the second to fourth speeds. This causes the forward clutch control valve 46 to open in the chamber 46.
A is supplied with pilot pressure from circuit 79 to maintain the state on the left side in the figure, and the forward clutch F/C is kept in a fully activated state without performing the pressure regulating action, thereby shifting from 2nd to 4th speeds. does not prevent ° from being selected. On the other hand, the control pressure of the circuit 97 is supplied to the chamber 30d of the lock-up control valve 30, and by determining this control pressure as described above by the computer via the duty solenoid 34, the lock-up control valve 30 is The torque converter 3 can be put into a humbatterer state, a slip control state or a lock-up state to match the operating conditions. (Third speed) After that, when the operating state is reached in which the third speed should be selected, the computer also turns off the second shift solenoid 44 and puts the second shift valve 4o in the left half state in the figure, as shown in Table 3 above. . As a result, the D range pressure that had reached 40g of boat passes through port 1-4Of, circuit 118, one-way orifice 120, and then one-way orifice 119.
The clutch is throttled and supplied to the high clutch H/C, which is activated. On the other hand, this pressure passes through the one-way orifice 122 via the circuit [21] branched from the circuit 11g, reaches the third-speed servo release chamber 3S/H, and deactivates the band brake B/B. 3-speed servo release chamber 3
The pressure to S/R is from chamber 52e of 4-2 sequence valve 52.
On the other hand, although this valve is placed in the left half state in the drawing to allow the boat 52c to communicate with the boat 52f, the circuit 116 continues to be drained because the second shift valve 40 communicates the boat 52r with the drain port 40i. Therefore, high clutch H
/C operation. Band brake B/B will be switched to non-operation,
As is clear from Table 1 above, the automatic transmission can select the third speed in conjunction with the operation of the forward one-way clutch FO/C. In addition, during this upshift from 2nd speed to 3rd speed, high clutch + (/C and 3rd speed servo release chamber 3
The pressure to S/R is throttled by the one-way orifice 119, and as mentioned above, the accumulator piston 66a, which is in the right half state in the figure, is pushed away against the line pressure in the chamber 66c, and thus increases. Shock can be prevented. (4th speed) After that, when the operating state becomes such that 4th speed should be selected, the computer turns the first shift solenoid 42 to O as shown in Table 3 above.
N, and the first shift valve 38 is switched to the right half state in the figure. As a result, the first shift valve 38 cuts off the circuit 113 to the 2nd speed servo apply chamber 2S/A from the D range pressure circuit 106, but it connects to the circuit 118 in the boat 38k and continues to the D range pressure circuit 113 to the 2nd speed servo apply chamber 2S/A. Although the range pressure is supplied and the circuit 126 is cut off from the drain port 38e, it is connected to the circuit 125 at the port 38j,
By passing through this and leading to the drain boat 40e, circuit 1
Continue to drain 26. The first shift valve 38 further communicates circuit 116 to circuit 118 via port 38h, 3812, and connects circuit 118.116 to circuit 118.
．． Port 58h. 58i0 circuit 135. By supplying D range pressure to the 4th speed servo apply chamber 45/A via the one-way orifice 186, the band brake B/B is switched to the operating state,
In combination with maintaining the operation of the forward clutch P/C and the forward clutch H/C, the automatic transmission can be placed in the fourth speed selection state as shown in Table 1 above. In this upshift from 3rd speed to 4th speed, the 4th speed selection pressure (highest speed selection pressure) to the 4th speed servo apply chamber 4S/A is throttled by the one-way orifice 136, as described above. Since the accumulator piston 68a in the right half state in the figure gradually rises while being pushed away against the back pressure in the chamber 68c, it is possible to prevent shock during the shift. Since the back pressure in the chamber 68c applied to the accumulator piston 68a is proportional to the engine output torque as described above, the above-mentioned shift shock reducing effect can be reliably achieved. In addition, the pressure supplied to the 4-speed servo apply chamber 4S/A (
4th speed selection pressure) reaches the chamber 66d of the accumulator 66. Thus, the capacity of the accumulator 66 during an upshift from the second speed to the fourth speed can be made different from the capacity of the accumulator 66 during an upshift from the second speed to the third speed to meet the requirements. is possible,
Thereby, the shift shock reducing effect can be appropriately performed even in the jump shift. (4→3 downshift) During the selection of the 4th speed, when the operating state becomes such that the 3rd speed should be selected, the computer turns off the first shift solenoid 42 and the first shift valve 38, as is clear from Table 3 above. Switch to the left half state in the figure. As a result, the same state as when the third speed was selected is reached, and the pressure in the fourth speed servo apply chamber 4S/A passes through the one-way orifice 136 and is quickly removed from the drain boat 401, causing a downshift to third speed. can be done. (4→2 downshift) During the selection of the 4th speed, when the operating state becomes such that the 2nd speed should be selected, the computer turns off the first shift solenoid 42 and the first shift valve 38, as is clear from Table 3 above. is switched to the left half state in the figure, and the second shift solenoid 44 is switched to the left half state in the figure.
is turned on to switch the second shift valve 40 to the right half state in the figure. By switching the first shift valve 38, the circuit 113 to the second speed servo apply chamber 2S/A is changed from the circuit 11B to the circuit 1.
The connection to 06 is changed and pressure is continuously supplied to the 2nd speed servo apply chamber 2S/A. Also, by switching the second shift valve 40, the circuit 118 changes to the D range pressure circuit 106.
The drain boat 40e is connected to the drain boat 40e. Therefore, the operating pressure of the high clutch H/C passes through the one-way orifice 119 and is removed from the drain boat 40e via the circuit 118 while being throttled by the one-way orifice 120, and the pressure in the third-speed servo release chamber 3S/R also passes through the one-way orifice 120. 122 and then eliminated through the same route. By the way, the pressure of 3rd speed servo release chamber 3S/H is connected to circuit 1.
The 4-2 sequence valve 52 guided by and responsive to the valve 24 remains in the left half state in the figure until the pressure is released, and drains the port 52c that communicates with the circuit 116 via ports 38i and 38h. It is cut off from the boat 52d and continues to communicate with the port 52f. Therefore, the pressure in the 4-speed servo apply chamber 4S/A connected to the circuit 116 is not eliminated.
The pressure in the third speed servo release chamber 3S/R is maintained until the release is completed. During this time, the pressure in the 4-speed servo apply chamber 4S/A is supplied to the 4-2 relay valve 50 via the circuit 116, and this valve is maintained in the right half state in the figure. Therefore, the pressure in the circuit 113 to the second speed servo apply chamber 2S is at port 50.
f, 50c, circuit 117. to port 40, 40h,
52f. 52c, 38i, 38h and circuit 116. port 5
8h, 58d, the pressure inside the 4-speed servo apply chamber 4S is maintained via the circuit 135. When the pressure in 3rd speed servo release chamber 3S/R is released, 4
-2 sequence valve 52 is in the right half state in the figure, and the port 52c is connected to the drain boat 52d, and the pressure in the 4-speed servo apply chamber 4S, which is connected to the circuit 116, is removed from the drain port 52d. As a result of this removal, the 4-2 relay valve 50 enters the left half state in the figure, and removes the pressure in the circuit 117 from the drain boat 50d. Thus, during the shift, the pressure in the 4th gear servo apply chamber 4S/A is removed after the pressure in the 3rd gear servo release chamber 3S/R and the high clutch l (/C is released), and the pressure in the former It is possible to prevent the pressure from being released before the latter pressure and shift from 4 to 3-2, and to reliably shift from 4 to 2. (3→2 downshift) In the third speed selection state When the operating state is reached in which the second speed should be selected, the computer turns on the second shift solenoid 44 and switches the second shift valve 40 to the right half state in the figure, as is clear from Table 3. Even if the boat 40h is connected from the drain boat 40i to the boat 40, the circuit 116 is connected in third gear.
(4-speed servo apply chamber 4S/A) is 4-2 in an unpressurized state.
Since the relay valve 50 is in the left half state in the figure and the circuit 117 is connected to the drain boat 50d, the boat 52f becomes the drain boat, and the 4-2 sequence valve 52 is connected to the 4-speed servo apply chamber regardless of the state. 4 Keep S/A in an unpressurized state. On the other hand, the above switching of the second shift valve 40 connects the circuit 118 to the drain boat 40e, and the high clutch H/C
And the pressure in the 3rd speed servo release chamber 3S/R is removed through the above-mentioned path during the 4-2 gear shift. Therefore, a downshift from 3rd speed to 2nd speed is obtained, but at this time, the pressure in the 3rd speed servo release chamber 3S/H is removed at a predetermined timing according to the engine operating condition as shown below. Smooth gear shifting is possible. That is, when the engine output torque is below a certain level, the correspondingly low D range pressure (line pressure) from the boat 56c puts the shuttle valve 56 in the left half state in the figure, and the chamber 48e of the 3-2 timing valve 48 becomes Since it is connected to the drain boat 56f via the circuit 133 and the boat 56e, the 3-2 timing valve 48 is in the left half state in the figure. Therefore, under this low engine output torque, the 3rd speed servo release chamber 3S/
The H pressure is released not only through the one-way orifice 122 but also through the orifice 48f, and the release speed is fast. When the engine output torque is above a certain level, the D range pressure (line pressure) from the high boat 56c corresponding to this puts the shuttle valve 56 in the right half state in the figure, and the 3-2 timing valve 48
is changed state by control pressure from circuit 109. The computer turns on the third shift solenoid 60 when the engine output torque and vehicle speed are higher than a predetermined value, and sets the control pressure to the same value as the pilot pressure, which is the original pressure. Therefore 3-
The 2-timing valve 48 is in the right half state in the figure, and the pressure in the 3-speed servo release chamber 3S/R is released at a low speed using only the one-way orifice 122. (2→l Downshift Shift) When the operating state becomes such that the first speed should be selected in the second speed selection state, the computer turns on the first shift solenoid 42 and turns the first shift valve 38 on, as is clear from Table 3 above.
Switch to the right half state in the figure. As a result, the circuit 113 to the 2nd speed servo apply chamber 23/A is connected to the D range pressure circuit 10.
6 and was cut off from boat 38r. 38k to circuit 118. By the way, circuit 118
is connected to the drain boat 40e by the second shift valve 40, the pressure in the second speed servo apply chamber 2S/A passes through the one-way orifice 114 and is quickly removed, resulting in a downshift from second speed to first speed. You can get variable speed. ■If the range driver desires engine braking in 2nd gear, etc., and sets the manual valve 36 to the manual range. Circuit 78 from boat 36II
Outputs line pressure. From boat 36D, the above-mentioned D
Pressure is supplied following the same path as in the case of a microwave oven, and the computer operates the 1st and 2nd shift solenoids 42.4.
The automatic transmission can be shifted between the first speed and the second speed by turning ON and OFF 4 according to Table 3 above to obtain either the first speed or the second speed. The pressure from the manual valve boat 36 (■) (range pressure) passes through the circuit 140 and reaches the boat 62c of the overrun clutch pressure reducing valve 62, placing this valve in the left half state in the figure. The range pressure from the circuit 140 further reaches the chamber 56g of the shuttle valve 56, locking this valve in the left half state in the figure. When the shuttle valve 56 is in this state, the control pressure of the circuit 110 is supplied to the chamber 58C of the overrun clutch control valve 58, and the computer uses this control pressure to turn off the third shift solenoid 60 to zero while selecting the second gear. The overrun clutch control valve 58 is in the left half state in the figure. Thus, the D range pressure from circuit 112 is transferred to circuit 137. Overrun clutch pressure reducing valve 62
It is supplied to the overrun clutch OR/C as a friction element via the circuit 138, and operates the overrun clutch OR/C, thereby making it possible to drive with engine braking in the second speed. For example, this engine brake is activated when selecting from D range 4th gear to ■ range, or from D range 3rd gear to ■ range.
Works when selected in the range. At this time, the overrun clutch pressure reducing valve B2 does not perform a pressure reducing action because it is in the locked state as described above, and the D range pressure, that is, the line pressure is supplied to the overrun clutch OR/C, and the line pressure is used as backup pressure. It is now possible to ■The range driver wishes to run with engine braking in 1st gear,
When the manual valve 36 is set to I range, this manual valve is connected to port 36D as shown in Table 2 above. The line pressure of the circuit 78 is output to 3611.38I. Pressure is supplied from port 36D through the same route as in the case of the D range described above, and the computer is supplied with pressure from the first. Turn on the second shift solenoids 42 and 44 to obtain the first or second speed according to Table 3 above. By turning off the automatic transmission, the automatic transmission can be shifted between the first speed and the second speed. Here, the reason why 2nd gear may be selected despite being in the ■range is that when the engine is reversely driven from the wheels while driving in the ■range, the engine may overspeed in the high vehicle speed range. To prevent this, under such conditions, first shift to second gear, then shift to first gear at a speed that does not cause engine overspeed.
Try to do it quickly. The pressure from the manual valve port 36II is controlled by controlling the shuttle valve 56 and the overrun clutch pressure reducing valve 62 from the circuit 109 by keeping the shuttle valve 56 and the overrun clutch pressure reducing valve 62 in the left half state in the figure, and controlling the overrun clutch control valve 58 from the circuit 109. Changes state depending on pressure. By the way, the computer sets this control pressure to 0 by turning off the third shift solenoid 60 in the I range, holds the overrun clutch control valve 58 in the left half state in the figure, and operates the overrun clutch OR/C. continue. The pressure from the manual valve boat 361 reaches the I-range pressure reducing valve 54 via the circuit 132, and this valve reduces the pressure from the circuit 132 to a constant value by the above action and outputs it to the circuit 131. By the way, the second shift valve 40 is in the right half state in the figure as shown in Table 3, regardless of whether it is in the first speed or the second speed, and outputs the pressure of the circuit 131 to the circuit 125. On the other hand, the first shift valve 38 is in the left half state in the figure as shown in Table 3 at the second speed, cutting off the pressure in the circuit 125 and communicating the circuit 126 to the drain port 38e. Thus, the circuit 130 to the low reverse brake LR/B passes through the shuttle ball 125 and the circuit 125 to the drain port 38e.
, and the low reverse brake LR/B is inactive. Therefore, operation of the overrun clutch OR/C enables engine braking running in the second speed. As mentioned above, when the vehicle speed reaches a point where the engine does not overspeed even in 1st gear, it becomes 1st gear.
The shift valve 38 is in the right half state in the figure, and the circuit 125 is connected to the circuit 126, and the pressure that reaches the circuit 125 is transferred to the circuit 1.
26. The shuttle ball 1271 is supplied to the low reverse brake LR/B via the circuit 130 to operate it. In this way, together with the fact that the overrun clutch OR/C is activated as described above, it is possible to run with engine braking in the first gear. Note that during engine braking in 1st and 2nd speeds, the overrun clutch pressure reducing valve 62 is locked in the left half state in the figure as described above, so it does not perform any pressure reducing action and the overrun clutch OR/ The operating pressure (backup pressure) of C is the line pressure. Also, during running with engine braking in the first gear, the pressure toward the low reverse brake LR/B is reduced to a predetermined value by the pressure reducing action of the I range pressure reducing valve 54, so the performance of the low reverse brake is adjusted to meet the requirements. As a result, engine brake shock can be prevented from occurring. FIG. 4 shows a backup pressure control device 200 of the present invention, which includes a throttle opening detection means 201, a vehicle speed detection means 202, and a range position detection means using an inhibitor switch (not shown) or the like. 203
, a coasting state detection means 204 using an idle switch or a negative pressure switch, and a gear position detection means 205 in the D range immediately before selecting the ■range or the ■range.
Detection signals from 11, 202, 203, 204, and 205 are input to the microcomputer 206. The microcomputer 206 includes a means 207 for determining the current driving range based on the signal from the range position detecting means 203, and a means 207 for determining whether the current driving range is in the coasting state based on the signal from the coasting state detecting means 204. means 208, means 209 for determining whether backup pressure is generated in the hydraulic pressure control device, that is, whether engagement pressure for overrun clutch OR/C or low reverse brake LR/B is generated; It includes means 210 for calculating backup pressure according to the state, and driving means 211 for duty-controlling the duty solenoid 24. FIG. 5 shows a flowchart for executing a program processed by the microcomputer 206, and this flowchart includes the steps shown in FIG. 6(A). Subroutines shown in (B), (C), and (D) are provided. Here, before explaining the flowchart of FIG. 5, the subroutine of FIG. 6 will be explained first. In addition, here, FIG. 5A will be temporarily referred to as a first subroutine, FIG. 2B as a second subroutine, FIG. 1C as a third subroutine, and FIG. In the first subroutine, a throttle value is read in step 1100, and step 1101 is performed based on this throttle value.
The line positive value is calculated in step 1102, and duty data for controlling the duty solenoid 24 is set. In the second subroutine, in step 1200, the vehicle speed Vsp
is read, line pressure is calculated in step 1201 from this vehicle speed Vsp and the backup data shown in FIG. 7, and duty data is set in step 1202. The backup data shown in FIG. 7 has two characteristics (D, select backup data (a) and D3 select backup data (b)) depending on the gear position immediately before shifting to the manual range. In subroutine 2, the line positive value is determined based on the D4 select backup data (a) which indicates a relatively high line positive value. Next, in the third subroutine, step 1300
D3 select backup data (b) which shows the relatively low line positive value shown in FIG.
Based on this, line pressure is calculated in step 1301, and duty data is set in step 1302. In the fourth subroutine, in step 1400, the duty data is simply set to θ, that is, the duty ratio (100%) is set so that the control pressure by the duty solenoid 24 is zero. Next, the main routine shown in FIG. 5 will be explained. First, in step 1000, it is determined whether the vehicle is in the driving range (D, n. (2) range), and if YES, the process proceeds to step 1001, where it is determined whether or not the vehicle is in the D range. If the result in step 1001 is No, that is, in the case of ■ range or ■ range, it is determined in step 1002 whether or not the coasting state is present. If it is in the coasting state (YES), it is determined in step 1003 whether or not backup pressure is being output, and in step 1003, it is determined that backup pressure is not being output (NO).
), proceed to step 004 and judge whether the gear position is D4 before shifting to the manual range, and if it is not D4 (NO), proceed to step 100.
5, it is determined whether the gear position before shifting is D3. If it is determined in step 1005 that the gear position before shifting is not higher (No), that is, if the gear position before shifting is Dt or higher, step 1
006, the first subroutine is executed in step 1006 to obtain duty data based on the throttle value, and duty is output to the duty solenoid 24 in step 1007 based on this duty data. On the other hand, in step 1001, the D range is set (
If it is determined that the coasting state is not present (No) in step 1002, the process proceeds to step 1008, where the backup flag is cleared to confirm that there is no need to output backup pressure, and the process proceeds to step 1008. The process advances to 1006 and similar processing is performed. Next, if it is determined in step 1004 that the pre-shift gear position is D4 (YES), that is, if the vehicle speed is significantly high, the process proceeds to step 1010, where the D4 backup flag is set, and the process proceeds to step 1011. In step 1011, the second subroutine is executed to set duty data based on the D4 select backup data shown in FIG. 7 and the vehicle speed, and in step 1007, duty is output. on the other hand,
If it is determined in step 1005 that the gear position before shifting is D3 (YES), that is, if the vehicle speed is
If it is slightly lower than the state, proceed to step 1020 and perform D3.
The backup flag is set and the process proceeds to step 1021. In step 1021, the third subroutine is executed to set duty data based on the D3 select backup data shown in FIG. 7 and the vehicle speed, and in step 1007, duty is output. On the other hand, if it is determined in step 1003 that the backup pressure is output (YES), step 1
Proceed to 030 and determine whether it is in 1st gear in I range. If it is in 1st gear (YES), that is, if backup pressure for 1st gear is supplied to low reverse brake LR/H, shift to I range. Since the backup pressure at the first speed is controlled by the pressure reducing action of the pressure reducing valve 54, there is no need to control the line pressure itself, and the process proceeds to step 1008, where the same process is performed thereafter. If it is determined in step 1030 that it is not the first gear (No), that is, if it is determined that the vehicle is in the ■ range or the second gear in the ■ range, the process proceeds to step 1031, and the backup when the engine brake is applied from the D4 gear. Determine whether pressure control is required. And the step 1
If D4 backup is required (YES) in step 031, the process advances to step 1010 and the same processing is performed thereafter. On the other hand, if it is determined in step 1031 that it is not a D4 backup (NO), that is, if it is a D3 backup, the process advances to step 1020 and the same processing is performed thereafter. By the way, in step 1000, it is not in the driving range (
If it is determined No, that is, in the case of P or N range, the process proceeds to step 1040, where the fourth subroutine is processed, and the process proceeds to step 1007, where line pressure control is skipped, and duty output is performed. By performing the above program processing, the backup pressure control device 200 of this embodiment has D range 4 speed (D
4) or when downshifting from 3rd gear (D, ) to 2nd gear in manual range or I range,
The duty ratio of the duty solenoid 24 is controlled according to the data shown in FIG. 7, and the line pressure is controlled via the pressure regulator valve 20. That is, when downshifting to the manual range 2nd speed, line pressure as backup pressure is supplied to the overrun clutch OR/C via the overrun clutch pressure reducing valve 62 as described above, and the engine brake is applied. do. By the way, the backup pressure (line pressure) in 2nd gear is the 8th
As shown in the figure, the line pressure is changed by the duty ratio control of the duty solenoid 24, and when the second gear engine brakes due to downshift from D, the line pressure When the 2nd speed engine brakes due to a downshift from D3, the line pressure is controlled according to the select backup data characteristics (b) in FIG. Therefore, even when the 2nd speed engine brake is applied, if the gear position before the shift is changed, the line pressure, that is, the backup pressure is set lower than in the case of D4. In other words, in the case of pre-shift gear position D4, the vehicle speed is set that high and the inertia force is large. Requires pressure, front R2D
The 4-select backup data characteristic (a) is set to satisfy this requirement, and at the same time, it is set so that unnecessary high pressure is not supplied so that no fastening shock is generated. On the other hand, if the gear position before shifting is D3, the vehicle speed is lower than in the case of D4, so D3
By setting the select backup data characteristic (b) lower than the D4 select backup data characteristic (a), overrun clutch OR/C and band brake B/
This prevents unnecessary fastening of B. Furthermore, even if the line pressure is controlled according to the select backup data characteristics (b) as described above, the settings must be such that overrun clutch OR/C and band brake B/B are prevented from slipping. Needless to say. Furthermore, in this embodiment, the above-mentioned D4. The D3 select backup data characteristics (11 ports) are set so that the line pressure increases according to the vehicle speed Vsp, and even when engine braking is applied from the same gear position, the higher the vehicle speed, the higher the backup pressure. control to prevent overrun clutch OR/C and band brake B/H from slipping, and the lower the vehicle speed, the lower the backup pressure to prevent overrun clutch OR/C and band brake B/B from engaging. is controlled in the direction of decreasing. Therefore, the backup control device 20 of this embodiment
At 0, the backup pressure is controlled according to the gear position and vehicle speed before shifting to manual range 2nd speed.
In addition, when the engine brake is applied in 2nd gear of the manual range, the overrun clutch OR/C and band brake B/B are prevented from slipping.In other words, the overrun clutch OR/C and band brake B are prevented from slipping while the engine brake is reliably applied. /H engagement shock, that is, shift shock during soft down, is significantly reduced. Furthermore, the backup pressure control device 200 of this embodiment is provided with coasting state detection means 204,
Based on the detection signal from this means 204, one basis is to determine whether or not to perform a backup, depending on whether the coasting state is present or not, as shown in step 1002 in the flowchart of FIG. Therefore,
If coasting is released by depressing the accelerator, that is, if drive torque is generated, step 10
At 08, the backup flag is cleared and line pressure control is performed in accordance with normal driving conditions (vehicle speed, throttle opening). Therefore, when the accelerator is turned on and the D range is selected again from the manual range, or when the ■ range is selected from the ■ range, etc., when upshifting, the high backup pressure is released and normal line pressure is generated, so the When the friction element is fastened, normal line pressure prevents the friction element from causing fastening shock. In this embodiment, the engine brake when downshifting to manual range I speed is controlled by ■ range pressure reducing valve 5.
Since the backup pressure controlled by hydraulic pressure in step 4 is supplied to the low reverse brake LR/H, the backup pressure control by the duty solenoid 24 is not performed when the engine brake is applied in this manual range 1 speed. However, the present invention is not limited to this, and the low reverse brake LR/B may be directly engaged by line pressure, and the line pressure may be controlled by the duty solenoid 24 even when the manual range is at l speed. As described in detail, in the backup pressure control device for an automatic transmission of the present invention, the backup pressure is controlled according to the vehicle speed when the automatic transmission range is selected from the manual range. As the vehicle speed increases, a higher backup pressure is supplied to the friction element that is engaged when the range is selected, and as the vehicle speed decreases, a lower backup pressure is supplied to the friction element. Therefore, when the engine brake is applied at high vehicle speeds, by supplying high backup pressure, the friction elements are reliably engaged without slipping by overcoming the large inertial force of the vehicle, and when the engine brake is applied, the friction elements are reliably engaged without slipping. By supplying a low backup pressure at low vehicle speeds, excessive engagement pressure is not supplied to the friction elements, significantly reducing engagement shock, or gear shift yoke, and greatly improving vehicle ride comfort. can do. In addition, by controlling the backup pressure, unnecessary pressure generation can be prevented, and as the load of pressure generation is reduced, fuel efficiency and power performance can be improved, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the concept of a backup pressure control device of the present invention, and FIG. 2 is an overall circuit diagram showing an embodiment of a hydraulic pressure control device for an automatic transmission in which the engine torque detection device of the present invention is used. FIG. 3 is a schematic diagram showing an embodiment of a power transmission train of an automatic transmission to which the hydraulic control device shown in FIG. 2 is applied;
FIG. 4 is a schematic configuration diagram showing an embodiment of the backup pressure control device of the present invention, FIG. 5 is a flowchart of an embodiment of executing the program of the backup pressure control device of the present invention, and FIG. 6(A), (B), (C), and (D) are flowcharts showing the subroutines of the flowchart shown in Fig. 5, Fig. 7 is a characteristic diagram of select backup data showing line pressure with respect to vehicle speed used in the present invention, and Fig. 8 9 is a characteristic diagram of line pressure with respect to the duty ratio of a duty solenoid, and FIG. 9 is a hydraulic characteristic diagram of a conventional backup pressure control device. 200... Backup pressure control device, 201... Throttle opening detection means, 202... Vehicle speed detection means, 2
03... Range position detection means, 204... Coasting state detection means, 205... Pre-shift gear position detection means, 206... Microcomputer, 20
7... Traveling range determining means, 208... Coasting state determining means, 209... Backup pressure determining means, 210... Backup pressure calculating means, 211...
Drive means, OR/C...overrun clutch (friction element). 2 outsiders Figure 6 (A) Figure 6 (B) Figure 6 (C) Figure 6 (D) Figure 7 Figure 8 Richi - Takumi (Shoulder Komon,)

Claims (1)

[Claims] (1) In an automatic transmission that supplies backup pressure to a friction element that is engaged when the automatic gear range is selected from the manual range, a means for detecting a vehicle speed when the manual range is selected, and a means for detecting the vehicle speed when the manual range is selected. 1. A backup pressure control device for an automatic transmission, comprising means for controlling backup pressure based on a detection signal from a detection means.